Squared magazine – A simple but photorealistic mockup of a squared magazine layout on a clean background. Available in Photoshop PSD files.
Office items – A mockup scenario that features black & white desktop stationery and paper. Available in 5 different PSD files from different angle views and arrangements. (behance.net)
Vintage photo effects – A Photoshop effects kit that gives you amazing vintage press-like effects: 10 color presets and 10 vintage press textures in two separate PSD files. (pixelbuddha.net)
Ballhead – Ballhead is a design concept that visualizes an app that hooks into the Dribbble or Behance platforms. Included in the concept pack are grid view model, carousel view mode, login screen, menu/navigation and pricing plan. (behance.net)
Routes – A set of 12 iOS app designs in Photoshop and Sketch files. (visualhierarchy.co)
iOS app screens – An awesome pack available in Sketch format containing 50 neatly crafted iOS UI screens for sign in, sign up, ad and onboarding experiences. (dribbble.net)
Aqua-style – A UI kit that features an aqua scheme with an artistic background pattern for its login form as well as feed, profile, statistic, and navigation bar screens. (behance.net)
FokiraDesh – FokiraDesh is a dashboard UI template in PSD format that features a nice flat, three-panel UI design. It also contains plenty of shortcodes to diversify your options.
Eco – Eco is a web UI kit that features a dark card style featuring red and green components, all of them in a seamless and smooth design.
Dink – Dink is a UI kit that comes with hundreds of components and UI compositions across 6 different categories neatly organized and consistent.
Mobile app material design – A user interface kit that features a nice material design low poly and that comes in PSD format, made out of fully scalable vector elements.
Wonder pastel gradient – Wonder is a mobile app UI kit that features a gradient scheme with pastel tones available in PSD format with 10 screen compositions in separate files.
Mobile app screens – Here is a cool mockup scenario for showcasing of mobile application screenshots featuring 6 layered screen placeholders in several strategic positions.
Orange Messenger App – A cool flat UI kit that featuresan Orange scheme. It comes with 6 screen compositions in PSD format for contacts list, menu, login screen, and more.
Materialui.co – materialui.co is a web tool for designers that feature material design colors, icons and flat UI colors collections available for direct download or color code copy-to-clipboard.
Core – CORE UI Kit comes with 12 fully editable high-quality screens of the 9 most common categories. This kit comes in PSD format including artboards to work with Adobe PS CC 2015.
U.S. Web Design Standards – An open source project that aims to collect and curate style guidelines used by US government sites.